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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
391

Analysis of the p53 Gene in Human Precancerous Actinic Keratosis Lesions and Squamous Cell Cancers

Nelson, Mark A., Einspahr, Janine G., Alberts, David S., Balfour, Celia A., Wymer, Julie A., Welch, Kevin L., Salasche, Stuart J., Bangert, Jerry L., Grogan, Thomas M., Bozzo, Paul O. 30 September 1994 (has links)
A biomarker of skin cancer would be beneficial in evaluating the efficacy of potential cancer chemoprevention agents. To this end, we investigated the tumor suppresser gene p53 in precancerous actinic keratosis lesions (AK) and malignant squamous cell carcinomas (SCCs) using polymerase chain reaction and single-strand conformation polymorphism analysis (PCR-SSCP) techniques. In addition, p53 protein expression was evaluated using immunohistochemistical analysis with the PAB 1801 monoclonal antibody. Nine out of 13 (69%) SCCs and 8 of 15 (53%) AKs were positive for p53 mutations. In contrast, normal skin samples were negative for p53 mutations. Sequence analysis of AKs and SCCs showed primarily C to T transition mutations. Nuclear immunochemical staining for p53 was observed in 12 15 (80%) AK and 12 13 (92%) SSCs. These results suggest that p53 mutations may be involved in the malignant conversion of AKs to SCCs and that p53 may be useful as a biomarker to study the potential modulatory effects of cancer chemopreventive agents against skin cancer.
392

Denaturants or Cosolvents Improve the Specificity of PCR Amplification of a G + C-Rich DNA Using Genetically Engineered DNA Polymerases

Varadaraj, Kulandaiappan, Skinner, Dorothy M. 01 January 1994 (has links)
We describe conditions that improve the specificity of amplification of a G + C-rich (57% G + C) DNA by PCR. Under standard conditions a 368-bp segment of the approx. 2.1-kb repeat unit of a satellite DNA that accounts for approx. 3% of the genome of the Bermuda land crab, Gecarcinus lateralis, was not amplified specifically. To establish optimal conditions for amplification of the segment of the G + C-rich satellite, we used two genetically engineered enzymes, AmpliTaq DNA polymerase and AmpliTaq DNA polymerase. Stoffel fragment (SF), and a number of denaturants or co-solvents. In the absence of denaturants or co-solvents, amplified products of both enzymes contained non-specific bands upon gel electrophoresis. Addition of certain denaturants or co-solvents to PCR mixtures resulted in the production of the single specific band of the expected size. Reagents that improved specificity of the amplified product were formamide, glycerol, DMSO, Tween-20 and NP-40; on the other hand, urea, ethanol and 1-methyl-2-pyrrolidone (NMP) inhibited amplification. Of the two enzymes, SF was more specific and efficient. The products of AmpliTaq DNA polymerase included one or more extra bands, even in the presence of denaturants or co-solvents, except for glycerol or DMSO.
393

Identification of the α<sub>1C</sub>-Adrenoceptor in Rabbit Arteries and the Human Saphenous Vein Using the Polymerase Chain Reaction

Diehl, Nicole L., Martin Shreeve, S. 16 August 1994 (has links)
The expression of the α1C-adrenoceptor subtype in human and rabbit blood vessels has been analyzed using the reverse transcriptase/polymerase chain reaction technique (RT/PCR). The 20 bp primers employed were designed from the bovine α1C-adrenoceptor and flank a least conserved region - the putative third cytoplasmic loop. RT/PCR products generated from rabbit and human brain mRNA both had 93% homology to the bovine α1C-adrenoceptor and were used as species and subtype specific probes in Southern blot analysis of vascular RT/PCR products. Poly A+ RNA was purified from the human saphenous vein and rabbit aorta, renal, pulmonary and central ear arteries and amplified by RT/PCR. Size analysis by agarose gel electrophoresis, together with Southern hybridization of the resulting cDNA products confirm the expression of the α1C-adrenoceptor in these vessels.
394

The formulation and refinement of a polymerase chain reaction (PCR) assay for early diagnosis of paediatric HIV infection and genetic analysis of variants involved in vertical transmission of HIV-1

Nolte, Jeanine Lucasta 19 April 2017 (has links)
Paediatric human immunodeficiency virus (HIV) infection has become a major socio-economic health problem in recent years as the number of HIV-1 infected children steadily increases. The majority of these infants are infected through mother-to-child transmission, with the frequency of vertical transmission varying between 12,9% and 65%. In order to implement appropriate management and possible treatment of these infected neonates, it is essential to have reliable laboratory tests for the early diagnosis of an HIV infection. At the time that this study was initiated, the diagnosis of HIV-1 infection in the Groote Schuur Hospital Virology Laboratory depended almost exclusively on serological assays. Such assays are of limited value for infants under 18 months of age, as maternal lgG antibody to HIV-1 is transferred via the placenta and may persist in the baby for up to 18 months. Available lgG antibody tests do not distinguish reliably between passively acquired maternal antibody and that produced by the infant itself. A valuable method of establishing the presence of true infection is provided by the polymerase chain reaction (PCR) technique which allows the identification, and subsequent exponential amplification of low levels of specific viral nucleic acid using specific oligonucleotide primers. A major aim of this study was to develop and instigate a (PCR) assay for the early diagnosis of HIV infection in infected infants. This was successfully achieved by the adaptation and optimization of an existing standard PCR protocol to suit the specific needs of a routine diagnostic service. Preliminary requirements involved the selection of primers and probes and establishing optimal parameters for: ionic strength, Taq DNA polymerase concentration, primer concentration, deoxynucleotide triphosphate concentration, and hybridization conditions for most efficient functioning of the test. The devised method entailed the extraction of proviral DNA from peripheral blood mononuclear cells, amplification of HIV-1 specific sequences by PCR, and identification by Southern blot hybridization with digoxigenin (DIG)-labelled probes. Thereafter the efficacy of the assay was tested on 45 infants (under 15 months of age) all born to seropositive mothers and therefore at risk for HIV infection. Forty-two of these infants had antibodies to HIV-1 and the remaining 3 were seronegative. The latter 3 also tested negative for HIV proviral DNA when PCR was performed, using at least 2 different HIV-1 primer pairs and their respective DIG-labelled probes. However, 27 (64%) of the 42 seropositive infants were also HIV-PCR positive and the remaining 15 (36%) seropositive infants were negative for HIV proviral DNA. Positive PCR tests correlated well with clinical data indicative of active HIV-1 infection for the majority of infants in the neonatal period, although it could not provide proof of infection in newborn babies (less than 1 week of age). The development of an in-house PCR protocol specific for HIV-1 has not only provided a valuable diagnostic assay for neonatal infection, but has also given insight into the parameters required for high sensitivity and the stringent precautionary measures that need to be applied to avoid contamination problems. The second part of this study was devoted to DNA sequence analysis of cloned HIV isolates from an infected mother and her 3-month-old infant. Nucleotide sequence variation between isolates of HIV-1 has been well documented. Examination of the third variable region (particularly the V3- loop) in the env gene of HIV-1 of our mother-infant pair confirmed this variation and provided the first genetic epidemiological data of this nature in the local community. Proviral DNA from both mother and baby was amplified using V3-specific degenerate primers and cloned. Clones containing the insert DNA were 2 identified by colony-blot hybridization. Their nucleotide and amino acid sequences were analyzed by using various computer programs. The degree of similarity between variants from the mother and infant in this study differed to a large extent from previous studies. The virus population harboured by the mother displayed highly homogeneous V3 sequences (1,04% variation) compared to the isolates from her 3-month-old infant, which showed a higher degree (1,8%) of heterogeneity. Phylogenetic analysis of the different isolates from mother and infant demonstrated that an HIV-1 subtype C virus was the infectious agent. This classification was confirmed by the characteristic amino-acid sequence of the tetrapeptide motif of the V3 loop present in the isolates from both mother and infant as well as the absence of a potential N-linked glycosylation site proximal to the first cysteine of the V3 loop, which is characteristic of subtype C viruses. Based on the amino acids present at positions 306 and 320 of the V3 loop, it could also be concluded that isolates from both the mother and her baby were consistent with the non-syncytium inducing (NSI) phenotype of HIV-1, thus indicating that, contrary to popular belief, NSI variants can be responsible for initiating infection. Data obtained from these genetic investigations of variants involved in vertical transmission of HIV-1 can form a useful basis for future comparative studies.
395

Detection of Campylobacter fetus in bovine preputial scrapings using PCR and culture assays

Schmidt, Tracy 13 May 2009 (has links)
The traditional method for the diagnosis of bovine genital campylobacteriosis is the culture and identification of the causative organism, Campylobacter fetus subsp. venerealis (Cfv) from the genital tract. This approach is considered relatively insensitive due to the fragility of the bacteria, their specific nutritional and atmospheric requirements and their being easily overgrown by commensal bacteria. The identification of isolates is also problematic due to the limited biochemical activity of the bacteria. With the rapid advances made in the molecular field, assays have become more robust and cost-effective making them feasible for the diagnostic laboratory. The potential speed, sensitivity and specificity offered by these assays provide attractive alternatives for the identification of pathogens which are notoriously difficult to identify. The first part of this investigation was concerned with the implementation and evaluation of a polymerase chain reaction (PCR) assay for the direct detection of C. fetus in bovine preputial specimens. The specificity of a published C. fetus-specific primer pair was established by testing C. fetus reference and field isolates in addition to a collection of other Campylobacter species and organisms which may encountered in the genital tract of cattle. All C. fetus isolates tested yielded a single PCR amplicon of approximately 750 bp. No amplicons were generated when any of the other non-C. fetus isolates were tested. Following minor modifications to the assay, the sensitivity of the assay was determined using spiked Weybridge medium. A detection limit of 615 Cfv/mR Weybridge medium (or 6,15 cell equivalents per PCR assay) was obtained. Preputial material collected and submitted for laboratory testing may often be contaminated with faeces, urine, semen and/or blood. All of these components are known to be potential PCR inhibitors and the influence of each, on the sensitivity of the PCR assay, was subsequently evaluated. Faeces were identified as a potent inhibitor and contamination of specimens with as little as 1% (w/v) faeces reduced the sensitivity of the assay. Concentrations of up to 50% (v/v) of blood, urine and semen had no effect on the sensitivity of the assay. Preputial specimens, collected in Weybridge medium, were subsequently pooled and spiked and used to establish the sensitivity of both the PCR and culture methods as well as determine the influence of time on the sensitivity of the assays. Testing was carried out in triplicate on samples collected from different herds which were ascertained to be free of Cfv based on the use of specific selection criteria. The detection limit of the culture method was found to be better than that achieved using PCR only immediately after the samples were spiked. The detection limit of the culture method decreased with time whilst the detection limit of the PCR assay remain unchanged up to 72 hours post-inoculation. Ensuing field evaluation involved the testing of 212 clinical samples using both the culture method and the optimized PCR assay. Of the samples tested 4,2% were found to be positive using the PCR assay, whilst only 3,8% were found to be positive by culture. Based upon this evaluation the analytical specificity of the PCR assay was calculated to be 99% and the analytical sensitivity, 85,7%. The second part of this investigation was concerned with the subspeciation of C. fetus isolates. Currently the only test recommended by the Office International des Epizooties (OIE) for the subspeciation of isolates, is tolerance to 1% glycine. Doubts over the reliability of this test have led to alternative or supplementary tests being sought. Within the context of this investigation a collection of 40 South African field isolates were subspeciated using a previously described subspecies-specific primer set as well as the traditional 1% glycine tolerance phenotyping test. Additionally, other phenotyping tests (selenite reduction, growth at 42 °C and susceptibility to metronidazole and cefoperazone) were evaluated to determine their suitability for use as an aid in the subspeciation of C. fetus isolates. None of the field isolates yielded a Cfv-specific subspecies PCR amplicon using the published primer set suggesting that all of the isolates were Campylobacter fetus subsp. fetus (Cff). Based on tolerance to 1% glycine however, only 6 isolates were identified as Cff (glycine tolerant), whilst the remainder were classified as Cfv. The results of the ‘sensitive’ hydrogen sulphide test indicated that the Cfv isolates were specifically Cfv biovar intermedius. The lack of agreement between the PCR and the phenotyping subspeciation results concur with the findings reported by other researchers. It is consequently concluded that the published VenSF/VenSR subspecies-primer set is unsuitable for the subspeciation of South African field isolates. / Dissertation (MSc)--University of Pretoria, 2008. / Veterinary Tropical Diseases / unrestricted
396

Development and evaluation of a real-time polymerase chain reaction assay for equine encephalosis virus

Rathogwa, Ntungufhadzeni Maclaughlin 22 November 2012 (has links)
Equine encephalosis virus (EEV) is the cause of equine encephalosis. The disease is similar to mild forms of African horse sickness (AHS) and the two diseases are easily confused. Laboratory identification and serotyping of EEV is based on viral isolation in BHK-21 cells and a viral plaque inhibition neutralization test (Erasmus <i<et al., 1970). These procedures require long durations to confirm results and it was desirable that a rapid diagnostic assay was developed to distinguish EEV from African horse sickness virus (AHSV). A PCR test developed for AHSV (Quan et al., 2008) formed the basis for development of a similar assay for EEV. The aim was to develop and evaluate a real time PCR assay for the detection of EEV in the blood and organs of horses. FastPCR software was used to design primers to amplify and sequence the EEV S7 (VP7) gene. RNA was extracted from EEV tissue culture isolates, representing all seven serotypes, using a MagMaxTM Express Particle Processor and MagMaxTM-96 Total RNA Isolation kits. A one step reverse transcription PCR (RT-PCR) was carried out to amplify the EEV S7 gene using a GeneAmp Gold RNA PCR core kit. Sequence reactions were carried out using a BigDye terminal v3.1 sequencing kit and analyzed with an ABI 3130xl Genetic Analyzer. After sequences alignment using BioEdit software, conserved regions were identified and Primer Express 3.0 software was used to design EEV primers and TaqMan® MGBTM hydrolysis probes for real-time RT-PCR assay. The EEV real-time RT-PCR assay was specific and did not detect AHSV nor bluetongue virus (BTV). The real-time format was selected because of its convenience, sensitivity and ability to produce results rapidly. Validation of the assay is the next step in establishing it as a routine diagnostic assay. Copyright / Dissertation (MSc)--University of Pretoria, 2011. / Veterinary Tropical Diseases / unrestricted
397

The demonstration of lumpy skin disease virus in semen of experimentally infected bulls using different diagnostic techniques

Bagla, Victor Patrick 27 May 2008 (has links)
Lumpy skin disease virus (LSDV), a poxvirus that belongs to the genus Capripoxvirus is an important pathogen that can be shed in the semen of infected bulls. The screening of semen for infectious virus prior to artificial insemination requires a sensitive diagnostic method. The isolation of the virus on cell cultures and/or the use of polymerase chain reaction (PCR) are sensitive diagnostic tests which can be used to screen semen for LSD viral DNA prior to artificial insemination. Although cell culture is a sensitive method and detects infectious virus, its use has major limitations due to the toxic effect of semen on the cells. This study was therefore aimed at finding a method that decreases the toxic effect of semen on cell culture and enhances LSDV isolation. Secondly, the efficiency of this method in enhancing the isolation of LSDV in field samples was tested. In order to eliminate the toxic effect of semen on cell culture, a pilot study was conducted in which semen samples from LSDV sero-negative bulls were collected and infected with a field isolate of LSDV, strain 248/93 with a titre of 6.5 log TCID50. The semen samples were subjected to one of four different methods, viz centrifugation, serial dilution, filtration and chemical treatment with kaolin. The centrifugation, serial dilution, and filtration methods were supplemented with additional amounts of gentamycin. The toxic effects of semen on cell culture were completely eliminated when supernatants of semen samples, centrifuged at 2000 rpm for 1, 3 and 5 mins and serial diluted was used to inoculate confluent monolayers of bovine dermis cells. Semen diluted in MEM with or without additional antibiotics was the most sensitive method of demonstrating virus at higher dilutions, followed by pellets of samples centrifuged for 1 and 3 minutes. The toxicity recorded when the pellet fraction of semen samples were centrifuged for 5 mins at 2000 rpm was comparable to results obtained from serially diluted samples supplemented with gentamycin. The use of filtration and kaolin treatment of semen samples could not remove the toxic effect of semen on cells. To evaluate the presence of LSDV in semen of experimentally infected bulls, six seronegative post-pubertal bulls housed in an insect proof facility were infected with LSDV via the intravenous route. The experimentally infected bulls were monitored for clinical sign of the disease. Two bulls showed severe, two a mild and two an inapparent infection. Blood samples were collected for virus isolation and semen samples for virus isolation and PCR. Vesicular fluid and preputial washes were also investigated for the presence of LSD viral nucleic acid using PCR. The infectious titre of the virus shed in semen of these bulls was also calculated. The incubation period in infected bulls varied from 7 to 14 days. The length of viraemia varied between groups and did not correlate with the severity of clinical disease. The virus was isolated from blood samples of bulls in the severely infected group on several occasions. Bulls in the mildly infected group had the lowest rate of isolated virus when compared to those with inapparent infection. The use of supernatants of centrifuged serial diluted semen samples, as shown in the pilot study, have considerably reduced the toxic effect of semen on cell culture. This method was used to test field samples for its sensitivity to isolated LSDV in semen of experimentally infected bulls with PCR as a gold standard. In all the semen samples tested using supernatants of semen samples LSDV was isolated in 53.1% of the samples on cell culture while in the serial diluted samples, only 28.1% of samples were positive with a median time of detection on cell culture of 4 and 8 days, respectively. The use of the supernatant fraction was able to detect infectious LSDV in semen samples for prolonged periods with reduced time of development of cytopathic effect, than previously reported. In order to compare the sensitivity of PCR and virus isolation, PCR positive and a few negative samples were subjected to virus isolation using the centrifugation method developed in the pilot study. The PCR was able to detect LSD viral nucleic acids in some semen samples even when virus could not be isolated on cell culture. The PCR was also able to detect viral nucleic acid in vesicular fluid and preputial washes of infected bulls. The titre of the virus shed in the semen at a certain stage of the infection was calculated to be 3 log TCID50. In conclusion, this study provides evidence of a complete reduction of the toxic effect of semen on cell culture and increase chances of LSDV isolation with reduced detection time when semen samples are processed using the centrifugation method as described in the pilot study. Furthermore, it showed PCR was more sensitive than virus isolation in the detection of LSD viral nucleic acid in semen samples and can be used for routine diagnosis. However, virus isolation must be used when the infective nature of virus shed in semen is desirable. This study provides the first evidence of the shedding of LSDV nucleic acid in vesicular fluid and preputial washes of experimentally infected bulls. It also represents the first report that a considerable amount of LSDV is shed in semen of experimentally infected bulls, which may be infective at certain stages of clinical disease. Lumpy skin disease virus (LSDV), a poxvirus that belongs to the genus Capripoxvirus is an important pathogen that can be shed in the semen of infected bulls. The screening of semen for infectious virus prior to artificial insemination requires a sensitive diagnostic method. The isolation of the virus on cell cultures and/or the use of polymerase chain reaction (PCR) are sensitive diagnostic tests which can be used to screen semen for LSD viral DNA prior to artificial insemination. Although cell culture is a sensitive method and detects infectious virus, its use has major limitations due to the toxic effect of semen on the cells. This study was therefore aimed at finding a method that decreases the toxic effect of semen on cell culture and enhances LSDV isolation. Secondly, the efficiency of this method in enhancing the isolation of LSDV in field samples was tested. In order to eliminate the toxic effect of semen on cell culture, a pilot study was conducted in which semen samples from LSDV sero-negative bulls were collected and infected with a field isolate of LSDV, strain 248/93 with a titre of 6.5 log TCID50. The semen samples were subjected to one of four different methods, viz centrifugation, serial dilution, filtration and chemical treatment with kaolin. The centrifugation, serial dilution, and filtration methods were supplemented with additional amounts of gentamycin. The toxic effects of semen on cell culture were completely eliminated when supernatants of semen samples, centrifuged at 2000 rpm for 1, 3 and 5 mins and serial diluted was used to inoculate confluent monolayers of bovine dermis cells. Semen diluted in MEM with or without additional antibiotics was the most sensitive method of demonstrating virus at higher dilutions, followed by pellets of samples centrifuged for 1 and 3 minutes. The toxicity recorded when the pellet fraction of semen samples were centrifuged for 5 mins at 2000 rpm was comparable to results obtained from serially diluted samples supplemented with gentamycin. The use of filtration and kaolin treatment of semen samples could not remove the toxic effect of semen on cells. To evaluate the presence of LSDV in semen of experimentally infected bulls, six seronegative post-pubertal bulls housed in an insect proof facility were infected with LSDV via the intravenous route. The experimentally infected bulls were monitored for clinical sign of the disease. Two bulls showed severe, two a mild and two an inapparent infection. Blood samples were collected for virus isolation and semen samples for virus isolation and PCR. Vesicular fluid and preputial washes were also investigated for the presence of LSD viral nucleic acid using PCR. The infectious titre of the virus shed in semen of these bulls was also calculated. The incubation period in infected bulls varied from 7 to 14 days. The length of viraemia varied between groups and did not correlate with the severity of clinical disease. The virus was isolated from blood samples of bulls in the severely infected group on several occasions. Bulls in the mildly infected group had the lowest rate of isolated virus when compared to those with inapparent infection. The use of supernatants of centrifuged serial diluted semen samples, as shown in the pilot study, have considerably reduced the toxic effect of semen on cell culture. This method was used to test field samples for its sensitivity to isolated LSDV in semen of experimentally infected bulls with PCR as a gold standard. In all the semen samples tested using supernatants of semen samples LSDV was isolated in 53.1% of the samples on cell culture while in the serial diluted samples, only 28.1% of samples were positive with a median time of detection on cell culture of 4 and 8 days, respectively. The use of the supernatant fraction was able to detect infectious LSDV in semen samples for prolonged periods with reduced time of development of cytopathic effect, than previously reported. In order to compare the sensitivity of PCR and virus isolation, PCR positive and a few negative samples were subjected to virus isolation using the centrifugation method developed in the pilot study. The PCR was able to detect LSD viral nucleic acids in some semen samples even when virus could not be isolated on cell culture. The PCR was also able to detect viral nucleic acid in vesicular fluid and preputial washes of infected bulls. The titre of the virus shed in the semen at a certain stage of the infection was calculated to be 3 log TCID50. In conclusion, this study provides evidence of a complete reduction of the toxic effect of semen on cell culture and increase chances of LSDV isolation with reduced detection time when semen samples are processed using the centrifugation method as described in the pilot study. Furthermore, it showed PCR was more sensitive than virus isolation in the detection of LSD viral nucleic acid in semen samples and can be used for routine diagnosis. However, virus isolation must be used when the infective nature of virus shed in semen is desirable. This study provides the first evidence of the shedding of LSDV nucleic acid in vesicular fluid and preputial washes of experimentally infected bulls. It also represents the first report that a considerable amount of LSDV is shed in semen of experimentally infected bulls, which may be infective at certain stages of clinical disease. / Dissertation (MSc (Veterinary Science))--University of Pretoria, 2006. / Veterinary Tropical Diseases / unrestricted
398

Environmental Variables Influencing the Severity of Pierce's Disease in California Grapevines

Boisseranc, Christopher James 01 June 2010 (has links) (PDF)
This project was designed to correlate environmental variables with the development of Pierce’s Disease (PD), an infection caused by the gram negative bacterium Xylella fastidiosa (Xf), in grapes (Hopkins et al. 2002). PD is one of the most difficult crop pathogens to manage because it is vectored by insects and its continued presence in the vine is usually fatal. PD is influenced by the interaction of host, disease and vector, and probably many other environmental variables. The general objective was to study and identify the most important variables involved in the expression of Pierce’s Disease. Over a two year period, from a total of eight sites in northern and southern California data was collected on forty-five environmental variables including those relating to soil moisture, soil chemistry, soil nutritional status, vine nutritional status, vine water status, in-season and dormant season climate, incidence of Xf in adjacent vineyard vegetation, sharpshooter species and abundance at each location, and proximity of vineyard field sites to citrus or riparian areas. The environmental variables were analyzed with canonical correspondence analysis (CCA) to determine significance of each as they correspond with increased disease severity. The significance of environmental variables produced by CCA indicates increased soil moisture as the leading cause for increased PD incidence; several other environmental variables positively correlate with increased disease presence. Conversely, vineyard factors identified by CCA as not conducive to disease formation may play an inhibitory role in PD severity. We undertook polymerase chain reaction (PCR) to test for the presence of PD in vegetative samples, using a 733 base pair probe specific to Xf. These samples indicate alternative hosts in adjacent locations which act as reservoirs of Pierce’s Disease as well as verifying diseased vines within the vineyard locations.
399

Optimizing a Quantitative Real-Time Polymerase Chain ReactionProtocol for the Characterization of Gene Expression in Blood VesselMimics

McGuffick, Tristin 01 November 2018 (has links) (PDF)
Blood vessel mimics (BVMs) are tissue engineered blood vessels that are intended as an intermediate testing environment for intravascular devices, such as stents. Specifically, Cal Poly’s Tissue Engineering Lab hypothesizes that BVMs can be used to test endothelial cell and smooth muscle cell responses to existing and new vascular stents. Characterization techniques are required for BVMs to be accepted as a valid testing model, prior to being employed as an in vitro model to determine the effects of medical treatments. Quantitative real-time polymerase chain reaction (qPCR) is one available option for evaluating gene expression of tissues. qPCR can be performed on DNA synthesized from RNA isolated from cells, and in this application, will provide quantitative information on what proteins where being transcribed within the cells at the time of RNA isolation. qPCR can be used to determine the proteins expressed in BVMs at baseline in order to then characterize changes in protein expression induced by stent deployment within the BVM. The aim of this thesis was to optimize existing qPCR protocols, and implement the optimized protocols to characterize gene expression of stented and unstented blood vessel mimics (BVMs) and cells from a donor with Diabetes grown in Cal Poly’s Tissue Engineering Laboratory. To accomplish this goal, existing qPCR protocols were evaluated and modified to ensure reproducible, valid results were produced. Standard operating procedures were created for RNA isolation, cDNA synthesis, qPCR and qPCR data analysis. Optimized qPCR methods were then applied to BVMs from umbilical and coronary cell sources to compare the models and to study the BVM responses to stent deployment. Additional primers were also identified for potential usage as reference genes and as diabetic markers for diseased BVMs.
400

Forensic DNA Extraction Strategies for PCR Analysis

Van Winkle, Carolyn 05 1900 (has links)
There is a transition nationwide on the analysis of forensic evidentiary stains containing biological material from traditional serology to Polymerase Chain Reaction (PCR) methodologies. The increased sensitivity of PCR, the limited number of alleles at each locus, and the necessity of producing unambiguous data for entry into the FBI's Combined DNA Index System make this study of extraction procedures of utmost importance. A "single tube" extraction procedure for blood stains collected onto FTA™ paper and a modified differential nonorganic extraction method from spermatozoa containing mixed stains were analyzed and compared. The extraction success was evaluated by amplification and typing of the amplified fragment length polymorphism, D1S80. These modifications of the nonorganic method utilized gave an improved separation of the spermatozoa-containing mixed stains.

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